In the field of semiconductor devices and microelectromechanical systems (MEMS), miniaturization is increasingly demanded. Accordingly, microfabrication techniques have recently attracted attention which uses a resist (photocurable composition) pattern having a specific shape on a substrate (wafer) as a mold, in addition to conventional photolithography techniques. The microfabrication technique, which is also called photo-nanoimprinting technique, enables the formation of fine structures of the order of several nanometers on the substrate (for example, PTL 1). In a photo-printing technique, first, a resist is applied to the region on a substrate to which a pattern will be formed (application step). Subsequently, the resist is formed into a pattern in a mold (mold contact step). Then, the resist is cured by being irradiated with light (irradiation step), and separated from the mold (mold-releasing step). Through these steps, a resin pattern (photo-cured product) having a specific shape is formed on the substrate. In addition, by repeating the sequence of the above steps for other regions on the substrate, a fine structure is formed over the entire surface of the substrate.
Unfortunately, the adhesion between the photo-cured product formed by curing a photocurable composition with light and the substrate is insufficient in some cases. The photo-cured product is therefore separated from the substrate and sticks to the mold when the mold is removed from the photo-cured product in the mold-releasing step of a photo-nanoimprinting process, and results in a defect of pattern separation.
To deal with this issue, a technique is devised for increasing the adhesion between the photocurable composition and the substrate by forming an adhesion layer between the photocurable composition and the substrate (PTL 2).
In PTL 2, an adhesion layer is formed of a composition containing a compound having a reactive functional group bound to a heterocyclic ring containing nitrogen and an unsaturated bond and capable of forming chemical bonds with a thiol group and an organic compound. Even in the case of using a composition containing such a compound, however, the adhesion between the photocurable composition and the substrate is not sufficiently increased in some cases, and pattern separation resulting in a defect can occur.